The gear hobbing process of face gear spherical hob is simulated by VERICUT software. Since the minimum number of undercutting of cylindrical gear with pressure angle of 25 ° is 12 and the minimum number of undercutting teeth of cylindrical gear with pressure angle of 20 ° is 17, the spherical hob corresponding to cylindrical gear will not undercut. In example 1, the blank width is set to be longer than the theoretical face gear tooth, so as to verify the phenomenon of tooth tip sharpening and tooth root undercutting. The face gear with the parameters shown in example 2 has been applied to the transmission device of a certain type of aircraft through gear shaping. Due to the limited space of the aircraft, the tooth length is limited. Take the middle part of the face gear tooth, with a length of 5 mm.
The spherical hob and face gear need to be driven in a fixed proportion, so the command “cgtech_macro” gearmodeonoff “1” is added to the G code of VERICUT software. The installation angles of the two examples are 2.492 ° and 2.2 ° respectively according to the formula. The simulation results of example 1 are shown in Figure 1. It can be found that there are unique undercutting and sharpening phenomena of face gear. Comparing the hobbing model with the gear shaping model, the maximum error is only 0.01 μ m. The error may be caused by the accuracy of tool modeling and the envelope residual of machining. The simulation hobbing results of example 2 are shown in Figure 2. Compared with the model obtained by gear shaping, the maximum error is 0.005 um.
